Abstract: Multimeric defensin proteins (MD) containing at least two defensin peptides joined by a spacer peptide that is resistant to endoproteinase cleavage are disclosed along with compositions comprising the MD proteins and transgenic or genetically edited plants or microorganisms that express the MD to inhibit growth of pathogenic fungi. Such MD proteins, compositions, plants, and microorganisms can provide for improved inhibition of fungal growth when compared to a protein containing only one of the defensin peptides found in the MD.